#include <opencv2/opencv.hpp>
#include <iostream>
#include <math.h>

using namespace std;
using namespace cv;

namespace chapter032 {

	Mat src, gray_src, drawImg;
	int threshold_v = 170;
	int threshold_max = 255;
	const char* output_win = "rectangle-demo";
	RNG rng(12345);
	void Contours_Callback(int, void*);
	int chapter032(int argc, char** argv) {
		src = imread("test.jpg");
		if (!src.data) {
			printf("could not load image...\n");
			return -1;
		}
		cvtColor(src, gray_src, CV_BGR2GRAY);
		blur(gray_src, gray_src, Size(3, 3), Point(-1, -1));

		const char* source_win = "input image";
		namedWindow(source_win, CV_WINDOW_AUTOSIZE);
		namedWindow(output_win, CV_WINDOW_AUTOSIZE);
		imshow(source_win, src);

		createTrackbar("Threshold Value:", output_win, &threshold_v, threshold_max, Contours_Callback);
		Contours_Callback(0, 0);

		waitKey(0);
		return 0;
	}

	void Contours_Callback(int, void*) {
		Mat binary_output;
		vector<vector<Point>> contours;
		vector<Vec4i> hierachy;
		threshold(gray_src, binary_output, threshold_v, threshold_max, THRESH_BINARY);
		//imshow("binary image", binary_output);
		findContours(binary_output, contours, hierachy, RETR_TREE, CHAIN_APPROX_SIMPLE, Point(-1, -1));

		vector<vector<Point>> contours_ploy(contours.size());
		vector<Rect> ploy_rects(contours.size());
		vector<Point2f> ccs(contours.size());
		vector<float> radius(contours.size());

		vector<RotatedRect> minRects(contours.size());
		vector<RotatedRect> myellipse(contours.size());

		for (size_t i = 0; i < contours.size(); i++) {
			approxPolyDP(Mat(contours[i]), contours_ploy[i], 3, true);
			ploy_rects[i] = boundingRect(contours_ploy[i]);
			minEnclosingCircle(contours_ploy[i], ccs[i], radius[i]);
			if (contours_ploy[i].size() > 5) {
				myellipse[i] = fitEllipse(contours_ploy[i]);
				minRects[i] = minAreaRect(contours_ploy[i]);
			}
		}

		// draw it
		drawImg = Mat::zeros(src.size(), src.type());
		Point2f pts[4];
		for (size_t t = 0; t < contours.size(); t++) {
			Scalar color = Scalar(rng.uniform(0, 255), rng.uniform(0, 255), rng.uniform(0, 255));
			//rectangle(drawImg, ploy_rects[t], color, 2, 8);
			//circle(drawImg, ccs[t], radius[t], color, 2, 8);
			if (contours_ploy[t].size() > 5) {
				ellipse(drawImg, myellipse[t], color, 1, 8);
				minRects[t].points(pts);
				for (int r = 0; r < 4; r++) {
					line(drawImg, pts[r], pts[(r + 1) % 4], color, 1, 8);
				}
			}
		}

		imshow(output_win, drawImg);
		return;
	}
}